Trimeric autotransporter adhesins (TAAs) are important virulence factors of many Gram-negative bacterial pathogens. TAAs form fibrous, adhesive structures on the bacterial cell surface. Their ...N-terminal extracellular domains are exported through a C-terminal membrane pore; the insertion of the pore domain into the bacterial outer membrane follows the rules of β-barrel transmembrane protein biogenesis and is dependent on the essential Bam complex. We have recently described the full fiber structure of SadA, a TAA of unknown function in Salmonella and other enterobacteria. In this work, we describe the structure and function of SadB, a small inner membrane lipoprotein. The sadB gene is located in an operon with sadA; orthologous operons are only found in enterobacteria, whereas other TAAs are not typically associated with lipoproteins. Strikingly, SadB is also a trimer, and its co-expression with SadA has a direct influence on SadA structural integrity. This is the first report of a specific export factor of a TAA, suggesting that at least in some cases TAA autotransport is assisted by additional periplasmic proteins.
Background: Autotransporter adhesins reach the bacterial cell surface by a complex mechanism.
Results: In the case of the autotransporter SadA from Salmonella, a lipoprotein assists in surface display.
Conclusion: The similarity to eukaryotic MATH domains suggests that the lipoprotein assists in trimerization of SadA.
Significance: Understanding the similarities between autotransport systems might lead to new ways of inhibiting bacterial adhesion.
Abstract
Objective:
Prior research examining the effect of hepatitis C virus (HCV) on health-related quality of life (HRQoL) and healthcare costs is flawed because non-patient controls were not ...adequately comparable to HCV patients. The current study uses a propensity score matching methodology to address the following research question: is the presence of diagnosed hepatitis C (HCV) associated with poorer health-related quality of life (HRQoL) and greater healthcare resource use?
Methods:
Using data from the 2009 US National Health and Wellness Survey, patients who reported a HCV diagnosis (n = 695) were compared to propensity-matched controls (n = 695) on measures of HRQoL and healthcare resource use. All analyses applied sampling weights to project to the US population.
Results:
HCV patients reported significantly lower levels of HRQoL relative to the matched-control group, including the physical component score (39.6 vs. 42.7, p < 0.0001) and health utilities (0.63 vs. 0.66, p < 0.0001). The number of emergency room visits (0.59 vs. 0.44, p < 0.05) and physician visits (7.7 vs. 5.9, p < 0.05) in the past 6 months were significantly higher for the HCV group relative to matched controls.
Conclusion:
The results of this study suggest that HCV represents a substantial burden on patients by having a significant and clinically-relevant impact on key dimensions of HRQoL as well as on utilization of healthcare resources, the latter of which would result in increased direct medical costs.
Limitations:
Due to limitations of the internet survey approach (e.g., inability to confirm HCV diagnosis), future research is needed to confirm these findings.
While the concept of angiogenesis blockade as a therapeutic intervention for cancer has been repeatedly demonstrated, the full promise of this approach has yet to be realized. Specifically, drugs ...such as VEGF-blocking antibodies or kinase inhibitors suffer from the drawbacks of resistance development, as well as off-target toxicities. Previous studies have demonstrated feasibility of specifically inducing immunity towards tumor endothelium without consequences of systemic autoimmunity in both animal models and clinical settings.
Placenta-derived endothelial cells were isolated and pretreated with interferon gamma to enhance immunogenicity. Syngeneic mice received subcutaneous administration of B16 melanoma, 4 T1 mammary carcinoma, and Lewis Lung Carcinoma (LLC), followed by administration of control saline, control placental endothelial cells, and interferon gamma primed endothelial cells (ValloVax™). Tumor volume was quantified. An LLC metastasis model was also established and treated under similar conditions. Furthermore, a safety analysis in non-tumor bearing mice bracketing the proposed clinical dose was conducted.
ValloVax™ immunization led to significant reduction of tumor growth and metastasis as compared to administration of non-treated placental endothelial cells. Mitotic inactivation by formalin fixation or irradiation preserved tumor inhibitory activity. Twenty-eight day evaluation of healthy male and female mice immunized with ValloVax™ resulted in no abnormalities or organ toxicities.
Given the established rationale behind the potential therapeutic benefit of inhibiting tumor angiogenesis as a treatment for cancer, immunization against a variety of endothelial cell antigens may produce the best clinical response, enhancing efficacy and reducing the likelihood of the development of treatment resistance. These data support the clinical evaluation of irradiated ValloVax™ as an anti-angiogenic cancer vaccine.
The current study characterizes health-related quality of life, work productivity, and resource use among postmenopausal women by severity of vasomotor symptoms (VMS).
Participants were selected from ...the 2010 US National Health and Wellness Survey. Women aged 40 to 75 years who did not report a history of menstrual bleeding or spotting for 1 year were eligible for analysis (N = 3,267). Cohorts of women with no VMS (n = 1,740), mild VMS (n = 931), moderate VMS (n = 462), and severe VMS (n = 134) were compared after controlling for demographic and health characteristics. Outcome measures were assessed using linear models and included health status, work productivity within the past 7 days, and healthcare resource use within the past 6 months.
The mean age of women experiencing severe VMS was 57.92 years. After demographic and health characteristics had been controlled for, women experiencing severe and moderate VMS reported significantly lower mean health status scores compared with women with no symptoms (P < 0.0001). The mean number of menopause symptom-related physician visits was significantly greater among women with severe, moderate, or mild symptoms than among women with no symptoms (P < 0.0001). Among employed women experiencing VMS, women with severe and moderate symptoms had adjusted presenteeism of 24.28% and 14.3%, versus 4.33% in women with mild symptoms (P < 0.001), and activities of daily living impairment of 31.66% and 17.06%, versus 6.16% in women with mild symptoms (P < 0.0001).
In postmenopausal women, a greater severity of VMS is significantly associated with lower levels of health status and work productivity, and greater healthcare resource use.
ValloVax is a placental endothelium derived vaccine which induces tissue-nonspecific antitumor immunity by blocking tumor angiogesis. To elucidate mechanisms of action, we showed that production of ...ValloVax, which involves treating placental endothelial cells with IFN-gamma, results in upregulation of HLA and costimulatory molecules. It was shown that in mixed lymphocyte reaction, ValloVax induces Type I cytokines and allo-proliferative responses. Plasma from ValloVax immunized mice was capable of killing in vitro tumor-like endothelium but not control endothelium. Using defined antigens associated with tumor endothelial cells, specific molecular entities were identified as being targeted by ValloVax induced antibodies. Binding of predominantly IgG antibodies to ValloVax cells was confirmed by flow cytometry. Further suggesting direct killing of tumor endothelial cells was expression of TUNEL positive cells, as well as, reduction in tumor oxygenation. Supporting a role for antibody mediated responses, cell depletion experiments suggested a predominant role of B cells in maintaining an intact anti-tumor endothelial response. Adoptive transfer experiments suggested that infusion of CD3+ T cells from immunized mice was sufficient to transfer tumor protection. Generation of memory T cells selective to tumor endothelial specific markers was observed. Functional confirmation of memory responses was observed in tumor rechallenge experiments. Furthermore, we observed that both PD-1 or CTLA-4 blockade augmented antitumor effects of ValloVax. These data suggest a T cell induced B cell mediated anti-tumor endothelial response and set the framework clinical trials through elucidation of mechanism of action.
In an international, randomized Phase III trial ipilimumab demonstrated a significant overall survival benefit in previously treated advanced melanoma patients. This report summarizes health-related ...quality of life (HRQL) outcomes for ipilimumab with/without gp100 vaccine compared to gp100 alone during the clinical trial's 12 week treatment induction period.
The Phase III clinical trial (MDX010-20) was a double-blind, fixed dose study in 676 previously treated advanced unresectable stage III or IV melanoma patients. Patients were randomized 3:1:1 to receive either ipilimumab (3 mg/kg q3w x 4 doses) + gp100 (peptide vaccine; 1 mg q3w x 4 doses; ipilimumab plus gp100, n = 403); gp100 vaccine + placebo (gp100 alone, n = 136); or ipilimumab + placebo (ipilimumab alone, n = 137). The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) assessed HRQL. Baseline to Week 12 changes in EORTC QLQ-C30 function, global health status, and symptom scores were analyzed for ipilimumab with/without gp100 vaccine compared to gp100 alone. Mean change in scores were categorized "no change" (0-5), "a little" (5-10 points), "moderate" (10-20 points), and "very much" (>20).
In the ipilimumab plus gp100 and ipilimumab alone groups, mean changes from baseline to Week 12 generally indicated "no change" or "a little" impairment across EORTC QLQ-C30 global health status, function, and symptom subscales. Significant differences in constipation, favoring ipilimumab, were observed (p < 0.05). For ipilimumab alone arm, subscales with no or a little impairment were physical, emotional, cognitive, social function, global health, nausea, pain, dyspnea, constipation, and diarrhea subscales. For the gp100 alone group, the observed changes were moderate to large for global health, role function, fatigue, and for pain.
Ipilimumab with/without gp100 vaccine does not have a significant negative HRQL impact during the treatment induction phase relative to gp100 alone in stage III or IV melanoma patients.
Clinicaltrials.gov identification number NCT00094653.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The prevalence of Type 2 diabetes mellitus continues to rise. Although glucagon-like peptide-1 (GLP-1) analog and dipeptidyl peptidase-4 (DPP-4) inhibitor medications are effective, there are ...differences between these products, including method of administration (injectable versus oral). The objective of this study was to examine patient preferences (and predictors of preferences) for two different medication profiles, one similar to a GLP-1 analog (liraglutide) and another similar to a DPP-4 inhibitor (sitagliptin).
Internet survey data were collected in two waves (wave 1, n = 2402; wave 2, n = 1340) using patients from the US and Europe. Patients were presented with two hypothetical medication profiles ("drug A" and "drug B", resembling sitagliptin and liraglutide, respectively) and asked to report their preferences.
Most patients in wave 1 and wave 2 reported that overall they would prefer a drug with the sitagliptin-like profile (81.9% and 84.4%, respectively) over a drug with the liraglutide-like profile (18.1% and 15.6%, respectively), and >80% of patients reported that they would be able to take a drug with the sitagliptin-like profile as directed by their physician for a longer period. The likelihood of preferring the sitagliptin-like profile significantly increased as age (odds ratio OR = 1.02) and importance placed on method of administration (OR = 1.32) increased (P < 0.05). Although the sitagliptin-like profile was preferred by the majority of patients in all subgroups, a lower proportion of patients with obesity, with weight gain, with A1C values above target, and who exercised preferred the sitagliptin-like profile compared with those without obesity (77.0% versus 87.9%), without weight gain (77.8% versus 86.7%), with A1C values at or below target (79.0% versus 86.5%), and who did not exercise (81.6% versus 86.4%), respectively (P < 0.05).
This research suggests that patients (across geographies) prefer an oral medication with a profile resembling sitagliptin to an injectable medication with a profile resembling liraglutide.
Virulence-associated type III secretion systems serve the injection of bacterial effector proteins into eukaryotic host cells. These effector proteins modulate host cell biology in order to promote ...colonization and infection, hence type III secretion systems are often essential bacterial pathogenicity factors. The core of type III secretion systems is a cell envelope-spanning macromolecular machine called injectisome. It consists of almost twenty different components in a stoichiometry of one to more than one hundred. Assembly of this 6 MDa complex requires the coordinated integration of components from the cytoplasm, the inner membrane, the periplasm, the outer membrane and even the extracellular space of Gram-negative bacteria. Here, we review injectisome assembly with an emphasis on the techniques that were employed towards its investigation. In particular, we focus on in vivo photocrosslinking, a technique that exploits the encoding of the artificial UV-inducible crosslinking amino acid p-benzoyl-phenylalanine to identify protein-protein interactions and to delineate assembly pathways.
Virulence-associated bacterial type III secretion systems are multiprotein molecular machines that promote the pathogenicity of bacteria towards eukaryotic host cells. These machines form needle-like ...structures, named injectisomes, that span both bacterial and host membranes, forming a direct conduit for the delivery of bacterial proteins into host cells. Once within the host, these bacterial effector proteins are capable of manipulating a multitude of host cell functions. In recent years, the knowledge of assembly, structure and function of these machines has grown substantially and is presented and discussed in this review.
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